To do this, you need not just fmap (composition), but also ap, or the combined form, liftA2:
func = liftA2 (||) Bob On 18 Apr 2010, at 18:21, Keith Sheppard wrote: > Using composition can be tricky with more than one arg. I just want to > be sure you're not really looking for something like: > >> func :: (a -> Bool) -> (b -> Bool) -> (a -> b -> Bool) > > keeping with your given type I think you're looking for something like: > >> func f1 f2 x = (f1 x) || (f2 x) > > I'm sure there is a nice way to do this with function composition but > I still find composition less intuitive than explicit args in cases > like this. > > On Sun, Apr 18, 2010 at 1:00 PM, Mujtaba Boori <mujtaba.bo...@gmail.com> > wrote: >> Thanks for helping me but I have another problem (sorry for asking) . I >> tried to figure it out . >> how about if I want to compare two kind with (&&) (||) for >> func :: (a -> Bool) -> (a -> Bool) -> (a -> Bool) >> >> I tried some thing like >> func = ((||) .) >> This is the annoying part about Haskell . I can not understand composition . >> >> On Sun, Apr 18, 2010 at 4:35 PM, Mujtaba Boori <mujtaba.bo...@gmail.com> >> wrote: >>> >>> Hello I am kinda newbie in Haskell you can help help me with some >>> programming >>> I am trying to make function like for example >>> func :: (a -> Bool) -> (a -> Bool) >>> this function make calculation and return bool . I want to be able to >>> make bool True when It is False and False when it is True while returning >>> the a. >>> Thank you >>> -- >>> Mujtaba Ali Alboori >> >> >> >> -- >> Mujtaba Ali Alboori >> >> _______________________________________________ >> Haskell-Cafe mailing list >> Haskell-Cafe@haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe >> >> > > > > -- > keithsheppard.name > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe